1. Field of the Invention
The present invention relates in general to the fields of building construction and interior decorating. More particularly, the present invention relates to a system and method for projecting light on a work surface to produce an image for tracing. Specifically, a preferred embodiment of the present invention relates to expediting the construction and installation of modular structures.
2. Discussion of the Related Art
Traditional means of constructing geometric designs and constructing and installing modular structures with edge detail required a multiple person crew. Extensive man hours were wasted tediously pre-assembling the entire structure on the floor, mounting and dismounting the structure and the edge detail to make it fit the work surface, aligning the structure in the air, and then raising it and holding it in place for final installation. During some installations, crew members could also take portions of the edge detail and mark points on the modular structure in order to define the perimeter of the finished pattern. These procedures also often ultimately relied on in the air adjustments which at times compromised the intended integrity of the patterns.
Moreover, pre-assembly on the ground limited the size of the structure which could be safely raised. Larger patterns would be too awkward to be raised by a practically sized crew of two or three people. Any additional laborers also have the disadvantage of relatively high cost.
As the construction industry is a competitive business, a preferred solution will be seen by the end-user as being cost effective. A solution is cost effective when it is seen by the end-user as compelling when compared with other potential uses that the end-user could make of limited resources.
Historically, it was known in the prior art to use of light sources of the type hereunder consideration, such as lasers, to aid in building construction. For example, lasers used for leveling are well-known to those skilled in the art. Further, the construction of trusses by following a projected pattern has been used previously in the construction industry. This process will be discussed in greater detail below. However, the use of these lasers in construction applications does not generally involve very complex patterns.
The below-referenced U.S. patents disclose embodiments that were at least in part satisfactory for the purposes for which they were intended. The disclosures of all the below-referenced prior U.S. patents in their entireties are hereby expressly incorporated by reference into the present application for purposes including, but not limited to, indicating the background of the present invention and illustrating the state of the art.
U.S. Pat. No. 5,430,662, entitled xe2x80x9cLaser Projection System for Truss Manufacturing,xe2x80x9d discloses a laser-enhanced design system for truss manufacturing. Lasers mounted on a ceiling project images onto a table below. The initial truss design is produced using a CAD system in conjunction with a work station or PC-microcomputer. A standard PC-microcomputer running MS-DOS software is used to control the laser system. Files required for the laser system are automatically created during the designing phase. An assembly line operator uses a mouse or keyboard to control and select the projected images while a worker places the truss elements over the projected images.
U.S. Pat. No. 5,388,318, entitled xe2x80x9cMethod for Defining a Template for Assembling a Structure,xe2x80x9d reveals a system for generating a template for use in assembling a structure such as a truss. One or more laser scanners mounted above a work surface are controlled by a computer to generate a scanning laser image of all or a portion of the structure. The computer receives data describing the relative location of the individual work pieces in their assembled positions and the position of the laser scanner relative to the work surface. The computer generates a set of template defining data which is converted to a control signal and transmitted to the laser scanner.
U.S. Pat. No. 5,663,885, entitled xe2x80x9cProcedure and Device for Processing Cutting Material,xe2x80x9d discloses a procedure for optimizing the processing of cutting material, such as textiles, leather and technical fabrics and the like, as well as to a device to perform the procedure. As shown in U.S. Pat. No. 5,663,885, the cutting patterns (T1, T2, T3) are first contained in the main memory of a computer (1) and then are selected. The selected patterns are projected on a cutting material on a working surface (AF) in their original size by means of direct laser projection, possibly with different colors, and are also projected on a control panel (4) in a scaled down size. The laser projections of the individual patterns are then interlocked on the cutting material by means of a control unit (5) actuated by an operator (P) positioned next to the cutting material. The patterns are interlocked to optimize use of the cutting material by accounting for the conditions of the cutting material, such as defective spots (F1, F2, F3, F4), and the shape of the cutting material. Once the patterns are finally positioned, data on these positions is then transmitted to a cutting unit, such as an automated cutter (C), by an instruction given by the operator and the citing operation is triggered.
U.S. Pat. No. 5,381,258, entitled xe2x80x9cLaser Projector for Projecting an Image Onto a Curvilinear Surface,xe2x80x9d discloses a laser projection system for projecting an image onto a surface comprises a laser projector operably connectable to a computer. The computer controls the operation of the system. The laser projector comprises a laser beam source for generating a laser light beam, a collimator comprising a focusing lens for focusing the laser light beam to a focal point, a collimating lens for collimating the laser light beam beyond the focal point and a wedge-shaped lens having an apertured interposed between the focusing lens and collimating lens. The aperture has a size for passing the laser light beam therethrough. Two scanners direct the light beam about a light path. A photo sensor receives light refracted by the wedge-shaped lens and generates a feedback signal. A plurality of target reflectors, each having a retroreflective material for retroreflecting light back to its source. The laser light beam is projectable in a predetermined pattern and if the laser light beam is retroreflected back to the laser light source, the retroreflected laser light beam is refracted by the wedge-shaped lens towards the photo sensor for generating a feedback signal for the computer. The plurality of target reflectors comprises a plurality of mountable targets for removably mounting on the surface. Upon striking the mountable targets with the laser beam, the photo sensor generates a plurality of feedback signals for establishing spatial coordinates of the mountable targets. The plurality of target reflectors further comprises a moveable target for inserting in the light path of the laser beam while projecting the image. Upon striking the moveable target with the laser beam, the photo sensor generates a feedback signal for limiting the area of projection of the image.
U.S. Pat. No. 5,341,183, entitled xe2x80x9cMethod for Controlling Projection of Optical Layup Template,xe2x80x9d reveals a projection system having a process utilizing three-dimensional data, thereby allowing the system to account for rotational and translational differences between the projector and the object upon which the laser light is directed. Reference sensors located on the object are in a known relationship to the three-dimensional data set to be projected, i.e., the reference sensors utilize the same coordinate system as the three-dimensional data set.
U.S. Pat. No. 5,757,500, entitled xe2x80x9cCalibration System for Large Tooling Fixtures,xe2x80x9d discloses a method for determining the position of a laser projector relative to a large tool which includes the use of posts having several reference points. A rotating tool is preferably also provided with a plurality of reference points. At least two of the reference points are spaced by a known distance. By identifying the location of the reference points, a control for the system is able to calibrate where the reference points are relative to the laser projectors. In this way, the laser projector is able to calibrate itself relative to the reference points on the large tool. The system initially determines the position of the reference points based upon known distances between the reference points.
U.S. Pat. No. 5,576,901, entitled xe2x80x9cDC Motor Actuator for Light Modification,xe2x80x9d discloses a light system which includes a laser light generator and an array of motor-driven mirrors aligned to deflect a beam of laser light in various directions to create a light show. The motors are operated in a controlled sequence by a motor controller. The motors are small DC permanent magnet motors which are driven from a DC source whose voltage is adjustable to vary the frequency of oscillation of the motors and, hence the mirrors. Connected to each motor is a small coil spring whose coil is carried on the motor shaft and which has two extended arms, one of which is secured to a nearly stationary member and one which is secured to the mirror shaft. The mirror shaft is movable between two stops. The spring acts to oppose the direction of motion of the motor such that the motor is normally stalled out and driven back to one of the stops before it can be moved for enough to impact the other stop.
U.S. Pat. No. 4,502,147, entitled xe2x80x9cMeans for Visually Indicating an X-Ray Field,xe2x80x9d discloses a visual indicator for an X-ray field which includes a light generator providing a beam of light. The light is provided to a first mirror that moves about an axis normal to the beam of light to deflect the beam. The deflected beam is applied to a second mirror that moves about an axis normal to the first axis and applies the beam of light to a mirror on the axis of the X-ray beam for reflection onto the X-ray field. The mirrors are controlled by signals indicative of the field defining collimator leaves to cause the light beam to trace out the field defining by the collimator leaves.
In one prior system, diode light sensors are used to align a structure to a laser projection coming from a projector mounted on a ceiling onto a gantry table. The table position is fixed. The projector and table never move. Whereas, for some particular jobs a system may be needed to cover an area (such as a ceiling) spanning thirty thousand square feet. Moreover, when one job is over, the system may be needed at another job site fifty miles away or a thousand miles away. Therefore, what is needed is a portable system which can be easily transported to another job. What is also needed is system which is able to project its own reference grid pattern onto the work surface (such as a ceiling) and can be easily aligned visually.
By way of summary, the present invention is directed to a system which brings accuracy and time savings to outlining a pattern for use in applications such as the construction and installation modular structures having edge trim detail. Preferably, this is accomplished by projecting an image of light onto a work surface. This light or laser projection system is compact and portable to allow mobility and flexibility when working within an occupied or active work environment.
Initially, a pattern or design is created by a designer, an artist, or architect. The design is then converted into a wire frame drawing file using any popular computer aided design (CAD) or bitmap drawing (BMP) software and a PC-based or Apple(copyright) Macintosh(copyright) based computer. The computer may be used to run both the CAD or BMP software and laser projection conversion software. The drawing file of the pattern is then dissected into workable sections. This dissection is necessary because of the limited available distance between the laser projector and the work surface at the installation site.
Next, the laser projection software loaded in the computer encodes the drawing file into a laser data file format. The software, aided by a specialized computer card, converts this digital laser data file information into an analog signal for output. The analog signal is then transmitted to a geometric signal conditioner. The geometric signal conditioner then transmits the analog signal to a laser projector. These analog signals control the positioning of scanners within the laser projector and the modulation of the laser light by on/off switching.
As the light projector emits an output image onto the work surface, the operator may physically move the projector into an optimal projection position. The xe2x80x9coptimal positionxe2x80x9d is in part defined by physical landmarks preferably identified during a site survey conducted at the installation location. Once this optimal positioning is roughed in, a second image is projected onto the work surface. This second image or target image is a grid pattern used to fine-tune the image""s, and eventually the pattern""s, precise alignment. A geometric signal conditioner is used for this procedure. The geometric signal conditioner is an electronic signal processor that modifies vector-scanning signals to compensate for oblique projection angles, non-planar surfaces, and scanner misalignment. Once the grid is visually aligned, the converted CAD file is loaded on to the computer and on to a specific sector of the pattern. That portion of the pattern is then projected onto the work surface.
The projected pattern image is then traced (usually by hand) onto the work surface. The projector may then be physically moved to the next sector. The projection of another test pattern allows the operator to once again roughly align the projector into place. The alignment grid is again manually or electronically fine-tuned with the geometric signal conditioner so that the next sector of the pattern is properly projected for tracing. Alternatively, multiple projectors can be simultaneously used to project the entire pattern upon the work surface for tracing.
An effect of the present invention is to provide greater placement accuracy during the installation of certain modular structures. Another object of the invention is to provide an apparatus that allows for dial-in placement accuracy of structures in near real-time, unlike the projection through a lens which cannot easily correct for unforeseen work site problems. Yet another object of the invention is to provide a system that is ruggedized and reliable, thereby decreasing down time and operating costs. Another object of the invention is to provide a system that has one or more of the characteristics discussed above but which is relatively simple to manufacture and assemble using a minimum of equipment. Still another object of the invention to provide an apparatus which is very mobile and easily transported from construction site to construction site.
Another object of the invention is to provide a system that incorporates many physical labor saving steps. Yet another object of the invention is to provide a system that is predictable and reproducible, thereby decreasing the possibility of variance and reducing overall operating costs. Another object of the invention is to provide a system that has one or more of the characteristics discussed above, but which is relatively simple to setup and operate.
These, and other, aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.